1. Field of the Invention
The invention relates to pressure measuring instruments and more particularly to a pressure gauge with improved characteristics.
2. Description of Related Art
Pressure gauges are widely employed in industries and daily life. For example, a pressure gauge can measure fuel pressure, atmospheric pressure, vacuum, atmospheric pressure in high altitude, or underwater pressure.
A conventional pressure gauge 1 is shown in FIG. 1 and comprises a base 10, a pressure measuring member 11 slightly above the base 10, a scale 12 supported by a raised member (not numbered) and further above the pressure measuring member 11, a hollow shaft 13 centered the pressure measuring member 11 and below the scale 12, a torsion spring 130 put on the shaft 13, a spindle 140 having a lower end disposed in the hollow shaft 13 and an upper end passing through a central opening of the scale 12, a spring actuated rotating member 14 rotatably put on the spindle 140, a lateral rod 15 put on the spindle 140 and biased by an upper end of the torsion spring 130, a screw 120 threadedly secured the scale 12 to an upper support 16 which has one portion engaged the upper sharp end of the spindle 140, a balance spring 141 around and secured to the rotating member 14, a spring actuated pointer 18 having one end rotatably secured to the rotating member 14, and a transparent cover 17 secured to a cylindrical housing (not numbered) which is mounted onto the base 10 so as to construct the pressure gauge 1.
However, the conventional pressure gauge 1 suffers a couple of disadvantages. In detail, the pointer 18 rotates irregularly and is no easy to reset for calibration. Thus, the need for improvement still exists.